System and method for preventing directly irradiating acoustic wave detector for photoacoustic imaging

Abstract

Provided is an object information acquiring apparatus including: a light source; a controller that controls irradiation of light from the light source; a detector that receives an acoustic wave generated from an object onto which light from the light source is irradiated; a processor that generates characteristic information inside the object using the acoustic wave received by the detector; and an acquirer that acquires the shape of the object, wherein the controller controls an irradiation area when light is irradiated from the light source onto the object, based on the shape of the object acquired by the acquirer.

The invention claimed is: 
     
       1. An object information acquiring apparatus comprising:
 a light source configured to generate light; 
 a controller configured to control a shape of an irradiation area of the light; 
 a controlling member configured to limit the irradiation area based on an instruction from said controller; 
 a detector configured to receive an acoustic wave generated from an object which is irradiated with the light; 
 a processor configured to generate characteristic information about a region inside the object using the acoustic wave received by said detector; and 
 an acquirer configured to acquire a shape of the object, 
 wherein said controller controls said shape of said irradiation area based on the shape of the object acquired by said acquirer so as to prevent said detector from being irradiated with the light without passing through the object, and 
 wherein said controlling member includes at least any one of a digital mirror device, a reflection type liquid crystal element, a transmission type liquid crystal element and a λ/2 plate. 
 
     
     
       2. The object information acquiring apparatus according to  claim 1 , further comprising a holding unit that holds the object,
 wherein said detector receives the acoustic wave from the object via said holding unit, and 
 said controller suppresses irradiation of light onto said detector outside an area on said holding unit where the object receives light orthogonally projected onto the object. 
 
     
     
       3. The object information acquiring apparatus according to  claim 2 , wherein said detector is acoustically coupled to the object via said holding unit interposed between said detector and the object, and receives an acoustic wave while scanning said holding unit. 
     
     
       4. The object information acquiring apparatus according to  claim 2 , wherein said acquirer is a camera that images the object contacting said holding unit. 
     
     
       5. The object information acquiring apparatus according to  claim 4 , wherein said controller detects a contour of the object by processing an image captured by said acquirer, and controls the irradiation area based on the contour. 
     
     
       6. The object information acquiring apparatus according to  claim 4 , further comprising a display unit that displays an image captured by said acquirer, and an input unit that receives input from an operator,
 wherein said controller controls the irradiation area based on information that the operator inputted based on an image displayed on said display unit. 
 
     
     
       7. The object information acquiring apparatus according to  claim 1 , wherein said processor generates image data about the region inside the object by reconstruction based on the characteristic information. 
     
     
       8. The object information acquiring apparatus according to  claim 1 , further comprising a scanner configured to move the light from the light source,
 wherein said controller controls an irradiation spot of the light in associated with a position of the light so as to define the shape of the irradiation area. 
 
     
     
       9. The object information acquiring apparatus according to  claim 8 , wherein the scanner moves the detector and the light source synchronously. 
     
     
       10. The object information acquiring apparatus according to  claim 8 , wherein the scanner includes a two dimensional stage which moves the irradiation spot of the light in two dimensional manner. 
     
     
       11. A control method of an object information acquiring apparatus including a light source, a controller configured to control irradiation of light from the light source, a detector, a processor and an acquirer, the control method comprising:
 a step of the acquirer acquiring the shape of an object; 
 a step of the controller controlling an irradiation area when the object is irradiated with light from the light source, based on a shape of the object acquired by the acquirer; 
 a step of the detector receiving an acoustic wave generated from the object which is irradiated with light from the light source; and 
 a step of the processor generating characteristic information about a region inside the object using the acoustic wave received by the detector, 
 wherein said step of controlling an irradiation area is performed such that said shape of said irradiation area is limited by using an area masking device based on the shape of the object acquired by said acquirer so as to prevent said detector from being irradiated with the light without passing through the object, and 
 wherein said area masking device includes at least any one of a digital mirror device, a reflection type liquid crystal element, a transmission type liquid crystal element and a λ/2 plate.